Electronic Components Datasheet Search |
|
XR19L222 Datasheet(PDF) 9 Page - Exar Corporation |
|
XR19L222 Datasheet(HTML) 9 Page - Exar Corporation |
9 / 53 page XR19L222 9 REV. 1.0.0 TWO CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER 2.2 5-Volt Tolerant Inputs The CMOS/TTL level inputs of the L222 can accept up to 5V inputs when operating at 3.3V. Note that the XTAL1 pin is not 5V tolerant when an external clock supply is used. 2.3 Device Hardware Reset The RESET or RESET# input resets the internal registers and the serial interface outputs in both channels to their default state (see Table 16). An active pulse of longer than 40 ns duration will be required to activate the reset function in the device. 2.4 Device Identification and Revision The XR19L222 provides a Device Identification code and a Device Revision code to distinguish the part from other devices and revisions. To read the identification code from the part, it is required to set the baud rate generator registers DLL and DLM both to 0x00. Now reading the content of the DLM will provide 0x01 to indicate functional compatibility with the XR16V2751 and reading the content of DLL will provide the revision of the part; for example, a reading of 0x01 means revision A. 2.5 Channel A and B Selection The XR19L222 provides the user with the capability to bi-directionally transfer information between an external CPU and an external serial communication device. During Intel Bus Mode (I/M# pin connected to VCC), a LOW on chip select pins, CSA# or CSB#, allows the user to select UART channel A or B to configure, send transmit data and/or unload receive data to/from the UART. Selecting both UARTs can be useful during power up initialization to write to the same internal registers, but do not attempt to read from both UARTs simultaneously. Individual channel select functions are shown in Table 1. During Motorola Bus Mode (I/M# pin connected to GND), the package interface pins are configured for connection with Motorola and other popular microprocessor bus types. In this mode the XR19L222 decodes an additional address, A3, to select one of the UART ports. The A3 address decode function is used only when in the Motorola Bus Mode. See Table 2. 2.6 Channel A and B Internal Registers Each UART channel in the L222 has a set of enhanced registers for control, monitoring and data loading and unloading. The configuration register set is compatible to those already available in the standard single 16C550 and dual ST16C2550. These registers function as data holding registers (THR/RHR), interrupt status and control registers (ISR/IER), a FIFO control register (FCR), receive line status and control registers (LSR/ LCR), modem status and control registers (MSR/MCR), programmable data rate (clock) divisor registers (DLL/ DLM), and an user accessible Scratchpad register (SPR). TABLE 1: CHANNEL A AND B SELECT IN 16 MODE CSA# CSB# FUNCTION 1 1 UART de-selected 0 1 Channel A selected 1 0 Channel B selected 0 0 Channel A and B selected TABLE 2: CHANNEL A AND B SELECT IN 68 MODE CS# A3 FUNCTION 1 N/A UART de-selected 0 0 Channel A selected 0 1 Channel B selected |
Similar Part No. - XR19L222 |
|
Similar Description - XR19L222 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |